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PIONEERS OF BLUE LEDS By Catherine Jewell, Communications Division, dazzle Nobel Committee WIPO WIPO | MAGAZINE p. 3 Photo: iStock © pawel.gaul

“Incandescent light bulbs had lit the 20th century; the 21st century will be lit by LED lamps.” Swedish Academy of Sciences. → p. 4 2014 | 6

hole

p-layer active layer n-layer

electron

wire bond anode cathode (p-electrode) (n-electrode) post anvil

p-GaN p-AIGaN Zinc-doped InGaN n-AIGaN n-GaN GaN Buffer Layer Sapphire Substrate anode Illustration: © Johan Jarnestad/The Royal Swedish Academy of Sciences Academy Swedish Royal Illustration: © Johan Jarnestad/The cathode Photos: © Swedish Academy of Sciences

A light-emitting diode consists of several Blue light emitting diodes (LEDs) are firmly embedded in our daily lives. They backlight layers : an n-type layer with a surplus of the screens of mobile phones, TVs and computers; they illuminate homes, streets negative electrons, and a p-type layer with an insufficient amount of electrons, also and vehicles and are used in an impressive array of other applications from Blu-ray referred to as a layer with a surplus of positive discs and traffic lights to digital communication and dentistry. This high-quality source holes. Between them lies an active layer to of light offers significant economic, social and environmental benefits. Some have which the negative electrons and the positive holes are driven when an electric voltage is put the impact of blue LEDs on a par with the transformations brought about by the applied to the semiconductor. When electrons invention of the traditional (incandescent) light bulb in the early 20th century. Others and holes meet they recombine and light have heralded blue LEDs as the “most successful semiconductor material of the 21st is created. The light’s wavelength depends on the semiconductor; blue appears at the century.” So it seems only fitting that this year’s Nobel Prize for Physics, an accolade short-wave end of the rainbow and can only that recognizes an invention of great benefit to humanity, has been awarded to its be produced using certain materials. inventors – Professor Isamu Akasaki, Meijo University and Nagoya University (Japan); Professor Hiroshi Amano, Nagoya University (Japan); and Professor Shuji Nakamura, University of California, Santa Barbara (USA).

Their seminal work in the mid-1980s sparked an intensification of research and devel- opment in the field, triggering a surge in patent filings as well as the rapid evolution of the technology, the emergence of a global multi-billion dollar industry and numerous far-reaching social and environmental benefits.

BREAKTHROUGHS SPAWN FIERCE BUSINESS RIVALRY In the early years, the two companies responsible for initially commercializing the technology – Toyoda Gosei (with whom Isamu Akasaki and Hiroshi Amano worked in partnership) and Nichia Corporation (Shuri Nakamura’s employer at the time) – domi- nated the lucrative market for blue LEDs. The two companies locked horns in a fierce business rivalry as each fought for pole position. Despite multiple rounds of litigation over patent rights (which ultimately resulted in a comprehensive cross-licensing agreement), their race for market dominance fuelled the technology’s rapid advance as each sought to outdo the other by producing brighter, higher quality blue LEDs. WIPO | MAGAZINE p. 5

The inventions of this year’s Physics Nobel Prize winners have revolutionized lighting technology. LEDs are extremely flexible sources of light capable of producing many different colors at varying intensities, as required. Breakthroughs in blue LED technology and its commercialization coincided with the growing popularity and explosive demand for mobile phones and liquid crystal displays. Huge sales and even bigger profits transformed the fortunes of both companies as well as those of Nagoya University. Thanks to Japan’s adoption of a law akin to the US Bayh-Dole Act, whereby universities gained ownership of patents deriving from government-funded research, Nagoya University was able to generate significant licensing revenue from its blue-LED-related patents. New market entrants including manufacturers of consumer electronics (e.g. Philips and Samsung) and innovative lighting solutions (e.g. Cree and Osram), seeking to tap into the technology’s huge commercial potential, added further impetus bringing about multiple advances in performance and an expanding range of applications which go far beyond those of conventional light sources.

LED TECHNOLOGY IN A NUTSHELL A LED is a solid state lighting solution. Unlike traditional incandescent bulbs where light is produced by heating a filament, a LED consists of several layers of (man-made) semiconductor material which, through a process of electroluminescence, converts electricity into light particles (photons). The wave-length of the light generated by a LED – its color – depends on the semiconductor material used; blue light which ap- pears at the short-wave end of the spectrum, and which is required to create white light, can only be produced using certain materials.

A white LED can be made either by mixing several colored LEDs or by using blue LED with a type of phosphor to create light that is white in appearance. A white LED bulb currently converts around 50 percent of the energy it uses into light compared to just 5 percent in an incandescent bulb. This makes it an increasingly favored, energy-efficient and environmentally friendly source of high-quality light.

A LITTLE LED HISTORY Red and greens LEDs, invented in the 1950s and 1960s, were created using galli- um arsenide phosphide; a material which proved unsuitable for creating blue LEDs. Recognizing the huge technological and commercial potential of blue LEDs (which would complete the palate of colors – red, green and blue - required to make white light), leading industrial labs invested significant time and resources into developing them, but to no avail. Harnessing the properties of the material gallium nitride (GaN), which is the basis for growing and mass producing the crystals needed to efficiently generate high-quality blue LEDs, proved difficult. It took some 30 years to crack the process. Researchers faced three key challenges: how to create high-quality crystals using GaN; how to change their conductivity; and how to boost their light emitting properties.

The lack of progress in working with the material caused many to abandon GaN research in favor of other seemingly more promising materials. But Isamu Akasaki, Hiroshi Amano and Shuji Nakamura remained convinced that GaN would yield the results they sought. Their dogged determination eventually paid off enabling them to succeed where others had failed. → p. 6 2014 | 6

LEDs use less power to emit light than traditional lighting 300 lm/W sources. As around one quarter of the world’s electricity consumption is used for lighting, energy- efficient LED light 70 lm/W sources can support efforts to tackle climate change. 16 lm/W

0,1 lm/W Illustration: © Johan Jarnestad/The Royal Swedish Academy of Sciences Academy Swedish Royal Illustration: © Johan Jarnestad/The Photo: © Swedish Academy of Sciences

OIL LAMP LIGHT BULB FLUORESCENT LAMP LED (approx. 15 000 B.C.) (19th century) (20th century) (21st century)

of LED lighting, the technology has the potential to reduce A NEW LED IS BORN annual energy costs by USD53 billion according to a recent In 1986, Isamu Akasaki and his (then) doctoral student Hiroshi PricewaterhouseCoopers’ report (http://tinyurl.com/optdh6k). Amano were the first to produce and patent high-quality blue LEDs (US Patent 4855249). The following year, they went into LED technology is also being used within the healthcare sector partnership with Toyoda Gosei Corporation under a project to help reduce energy costs and inhibit the spread of infections funded by the Japan Science and Technology Agency (JST) to within hospitals. Its use in managing pain, insomnia and various further develop GaN-related blue LEDs. Toyoda Gosei began behavioral disorders and illnesses, including Alzheimer’s, is commercial production of its blue LEDs in 1995. also being explored.

Independently of the Nagoya researchers, Shuji Nakamura It also holds promise in alleviating the “broadband crunch” re- (then employed by Nichia Corporation) began developing his sulting from current mass data usage. LiFi, the latest technique own blue LEDs (US Patent 5290393) and the techniques and in the field of optical wireless communications, “focuses on processes for their large-scale production. In November 1993, establishing communication links via LED lighting networks,” a Nichia became the first company to commercially produce report by the technology consultancy iRunway explains (http:// high-quality blue LEDs. tinyurl.com/muz9crg).

A year later, drawing on its chemical expertise, Nichia produced A FERTILE ENVIRONMENT FOR PATENTS the world’s first white LEDs by combining yttrium aluminium garnet phosphor with blue LEDs (US Patent No. 5998925). The Japanese-born scientists’ groundbreaking work sparked These breakthrough developments spawned the growth of a renewed global interest in blue LEDs and a surge in patenting multi-billion dollar global industry and triggered a seismic shift activity. Patents continue to be an important means by which in the traditional lighting sector. companies involved in the development and production of LEDs are able to protect their intellectual property (IP) rights and their market position. “Patents are very important because they give MULTIPLE BENEFITS; WIDE-RANGING APPLICATIONS companies a competitive advantage in the marketplace,” notes White LED light bulbs are a high-quality, energy-efficient and Professor Nakamura. environmentally-friendly light source. They are around 20 times more efficient than conventional bulbs generating around 300 A recent study by iRunway found that since the early 1990s in the lumens per watt – a 40 watt incandescent bulb produces US alone, around 22,662 patents have been granted in the LED just 450 lumens – with a lifespan of around 100,000 hours – field – 17,869 of those relating to LED technology and 4,793 of compared to around 1,200 hours for an incandescent bulb. them relating to the application of the technology. “The breadth They can also operate using cheap local solar power, making and complexity of technologies and applications of LED, and it possible to light up the lives of over 1.5 billion people who the innovation needed to bring them all together, have resulted currently lack access to electricity grids. in aggressive patenting activity over the years,” the study notes.

As lighting accounts for around 20 percent of the world’s elec- PATENT LITIGATION IS COMMON tricity consumption (around 6 percent of greenhouse gas emis- sions), the widespread uptake of LED bulbs promises to signifi- Patent litigation is a common feature of the LED sector. In cantly reduce global electricity consumption. In the US alone, if the early days, Nichia Corporation and Toyoda Gosei set the energy usage for lighting is cut by 40 percent with the uptake tone, suing and counter-suing each other in some 10 LED WIPO | MAGAZINE p. 7

patent-related lawsuits over six years. From 1996 to 2010, 168 competition between inventors or the advancement of science LED-related patent lawsuits were filed worldwide according and technology,” explains Professor Yasumasa Iwatani, a close a 2013 paper by Amy J.C Trappey et al. in the International colleague of Professor Akasaki at Meijo University. Journal of Automation and Smart Technology (www.ausmt.org) The LED sector remains in “active litigation mode” with major BLUE LEDS AND THE PCT players currently involved in “almost three active litigations per company” according to iRunway. A significant number of GaN-based LED patent applications, as well as key pioneering patents filed by this year’s laureates have passed through WIPO’s Patent Cooperation Treaty (PCT). LICENSING AGREEMENTS This is a cost-effective mechanism for applicants (individuals, Licensing and cross-licensing agreements remain the means companies or universities) seeking patent protection in multiple by which many patent disputes are settled within the industry. countries. “The advantage of the PCT is that it is easy to expand “Patent licensing has been one of the leading impetuses for the patent right to other countries in order to protect the right of international technology transfer,” Amy Trappey et al note. the inventor,” notes Nagoya University’s Hiroshi Amano.

Patent licensing deals, however, also enable companies in a “University technologies are generally very early stage. The PCT competitive market to avoid patent infringement and costly is critical for these early stage technologies because it gives us litigation. Toyoda Gosei, for example, has from the outset been the opportunity to protect our patents globally while allowing favorably disposed to licensing its technologies to other com- the market and the technology to mature further before deter- panies. The company is currently licensing, in collaboration with mining which countries might be most valuable to commercial its international partners, a white light technology patent using partners,” Professor Nakamura explains. blue LED and silicate phosphor to over 30 LED manufacturers according to a recent report by LEDinside (www.ledinside.com). A simple search of WIPO’s Patentscope – a free public database hosting over 43 million patent applications – for GaN-related While the most basic LED patents are currently controlled by blue LED patent applications indicates that over 8,250 interna- key industry players – Philips, Nichia, Osram, Toyoda Gosei and tional applications were filed during the period 2004 to 2013. Cree – enabling them to effectively “control the industry supply A similar search revealed that Professors Nakamura, Akasaki chain,” and making it difficult for new market entrants, many of and Amano have filed 207, 65 and 53 patent applications re- these patents (including US Patent 5998925) relating to white spectively over the years. LED manufacture) are due to lapse in the coming years, signal- ing potential changes to LED market dynamics and structure. The pioneering achievements of Professors Akasaki, Amano and Nakamura, are transforming the global lighting industry and have given rise to a broad range of applications in other TECHNOLOGY TRANSFER areas, including, consumer electronics. “Incandescent light Patents continue to be instrumental in transferring technology bulbs had lit the 20th century; the 21st century will be lit by LED within and across the industry through licensing and cross- lamps,” notes the Swedish Academy of Sciences. LED lights licensing agreements. They also enable the transfer of technol- are fast becoming the lighting source of choice. By 2020, LED ogy from university research labs to industry. For example, as bulbs are expected to occupy around 70 percent of the lighting holders of patents covering their breakthrough blue LED tech- market, the value of which is expected to rise to EUR83 billion nology, Isamu Akasaki and Hiroshi Amano at Nagoya University (Mckinsey 2012). The impact of the achievements of this year’s were able to license it to their industrial partner, Toyoda Gosei. Nobel Physics laureates is far-reaching and dramatic, promising By 2006, Nagoya University’s GaN-related blue LED licensing significant environmental benefits on top of significant energy revenue rose to around JPY5.6 billion (around USD48 million and cost savings. The on-going technological and commercial in today’s money) representing at the time around 90 percent dynamism of the sector suggests that the party is far from over. of royalties from government-held patents. These revenues It may have only just begun. ◆ have funded the establishment of the University’s cutting-edge semiconductor research facility. “Patents […] give universities a mechanism for transferring technologies they develop to the market through appropriate commercial partners. This way, important university innovations can be turned into products that will benefit society. Without the competitive advantage that patents offer, companies would not have the same motivation to commercialize these products,” explains Professor Nakamura.

“Through the patent system, inventors and companies are able to retain exclusive rights to their inventions for a certain period of time, which allows them to present these inventions to the world via academic conferences and scientific papers. Without the patent system, I believe there would be no room for friendly